Huckaby's College Football Ratings

The ratings are calculated in a two part
process combining a team's results for the year and the team's seeding for the
year. I'm not going to get into mathematical specifics here, but here's an
overview:

A team's raw power rating is calculated by combining their winning percentage
with an estimate of their winning percentage using an offshoot of Bill James'
Pythagorean theorem. Fudge factors are included in order to at least somewhat
be able to handle teams that are unbeaten, untied, and unscored upon. The raw
power rating is modified according to the average power rating of the
opposition, then by the opposition's opposition's average power rating, etc.
until the (opposition)^n's power rating converges for all teams being rated.

In order to be able to have reasonable ratings during the beginnning of the
season, the system calculates pre-season power ratings or seedings at the beginning of
each year. For more detailed information, click here.

The pre-season seeding is combined with the modified power rating in a function
that decreases the impact of the seeding as the season goes by. The pre-season
seeding never goes away completely, but has very minor impact on the power
ratings at the end of the year.

The power rating is defined as the chance the team has to beat an average
Division 1-A team with no effect from location. This, a team with a .700 power rating
has a 70% chance to beat an average Division 1-A team at a neutral site.

The ratings are calculated using a spreadsheet. The ratings do not use
results on a game by game basis; rather, they use seasonal totals
and schedules. The chance a team wins can be calculated based on the power ratings of
the teams in the game and the home field advantage,
and an expected pointspread can be calculate if you know the amount of points expected
to be scored in the game.